GREEN BAY, Wis. -- If there's one thing you should know about Aaron Rodgers, it is this: He plays to stick it to anybody and everybody who had the nerve to once doubt him.

You don't think he's noticed what a nightmare season it's been for a certain NFL quarterback in a certain other city? You don't think he's watched that painful, very public downfall with interest -- and maybe with a slight I-told-you smile?

Rodgers is all about getting even, proving that he was right and you were wrong. It's a useful tool in this league, and it's partly why Rodgers' Green Bay Packers are going to the playoffs while that beleaguered quarterback in that other city isn't.

But the other quarterback isn't Brett Favre. Favre is the last reason Rodgers spent the longest 4 hours, 35 minutes of his life stuck in the green room of the Jacob Javits Center in April 2005. In fact, without Favre and his annual career indecision, Rodgers' agonizing NFL draft day wait might have lasted even longer.

Aaron Rodgers even led the Packers with 21 yards rushing in Sunday's win over the Bears. Jeff Hanisch/US Presswire

No, Rodgers has a jones against his boyhood favorite San Francisco 49ers, who chose Alex Smith with the No. 1 pick that year. Smith got the huge contract, the first photo op with then-NFL commish Paul Tagliabue and a personalized jersey to hold for the cameras. Rodgers got nationally televised humiliation as he dropped from the potential first overall selection to the 24th. When it came time for him to finally pose with Tags, someone hurriedly handed him a Packers jersey -- with no name on the back.

"It was brutal watching that," said Packers wide receiver Greg Jennings, who was drafted a year later. "Obviously we see what kind of resolve he has."

Resolve is a nice way to put it. The truth is that Rodgers was insulted then and remains insulted now. He hides it well, but Sunday's wild-card game against the Philadelphia Eagles is another chance to pour a box of Morton into the Niners/Smith draft day wound.

"I did watch when Aaron didn't get drafted early," Packers running back Ryan Grant said. "I do remember Aaron sitting there. He's definitely got a chip on his shoulder. That's what you want."

The chip was on display immediately after the Packers chose him in 2005. You know what he told reporters?
"I still think I'm the best quarterback in this draft," he said.

Six seasons later, he's right. He's way better than Smith, who has never reached the playoffs, never had a winning record and never kept the starting job two full seasons in a row. Smith is going on his third head coach and another offensive system.

"It just didn't make sense that a player like this would drop like this," said then-first-year Packers general manager Ted Thompson at the time.

It didn't make sense to Rodgers, either. Still doesn't. (Retrospective question: Would Thompson have taken Smith had he dropped to No. 24?)

Rodgers is driven by that draft day snub, by all snubs. He vowed he would exact some form of revenge on each of the 23 teams that passed on him. In his three seasons as a starter, Rodgers has beaten nine of the 23, including San Francisco twice.

The Niners shouldn't be offended. Rodgers has a long history of carrying grudges. He was ignored early in his career at Pleasant Valley High School in Chico, Calif. He received exactly zero Division I, II and III scholarship offers out of high school. Cal signed him out of junior college, but it was more accident than great scouting.

When he arrived at his New York hotel for the 2005 pre-draft functions, a fan asked, "Hey, Alex, will you sign this?"

Packers center Scott Wells saw that draft unfold on TV. He said he felt sorry for Rodgers, "but I was happy to get him here."

Without Rodgers, the Packers would be a subcompact car with leather seats. Without Rodgers, said Jennings, the Packers "would probably [be] watching next week."

Instead, they'll travel to Philly to face a team they beat in Week 1 -- pre-Michael Vick As Starter. And with each playoff appearance and each win, Rodgers puts a little more distance between himself and Smith. And Favre.

Still, nothing has come easily for the Packers this season. Grant's season-ending ankle injury in September (and no real replacement) has crippled the Packers. Rodgers is the team's second-leading rusher in 2010. Against the Chicago Bears in Sunday's play-in win, he led Green Bay in rushing -- with 21 yards.

Rodgers has played hurt, and if it were up to him, he would have played woozy. He has suffered two concussions this season, the second one costing him a start at New England. The Packers lost.

He is the only indispensable Packer. He is what Favre used to be and what the 49ers hoped Smith would become.

Rodgers and the Packers have squeezed their way into the playoffs despite losing six starters to injuries from the season's beginning. Fourteen Packers are on the injured reserve. Yet they've won 10 games, including essentially elimination games against the Bears on Sunday and the New York Giants the week before that.

"I think it says a lot about the kind of men we've got from the top floor down," Rodgers said. "Guys made tough decisions, and we've stuck together, followed our coaches and believed in each other. I think it says a lot about the guys who stepped up."

This is Rodgers' team and Rodgers' town. And in many ways, 2005 turned out to be Rodgers' draft. He sat behind Favre for three seasons, but he was planning even then. Just ask Jennings.

"I remember when I got drafted here," Jennings said. "I walked into the cafeteria -- and had never met the guy a day in my life -- and the first thing he said to me was, 'It's going to be you and me sometime in the future.'

"And here we are in the future."

The future continues Sunday against the Eagles. As always, Rodgers will be there with a point to prove.

Gene Wojciechowski is the senior national columnist for ESPN.com. You can contact him at gene.wojciechowski@espn.com. Hear Gene's podcasts and ESPN Radio appearances by clicking here. And don't forget to follow him on Twitter @GenoEspn.